Shear demand and shear deformation in exterior beam-column joints

Abstract

The entire researchers till 1970’s believed that RCC beam-column joints behave as rigid joint. So in none of the pre 1970 building codes, they had not provided the confining reinforcement in the joints. With lot of damage and destruction of building due to shear force under earthquakes most of the code committee has introduced the confinement in the joints. But recently due to use of high grade of concrete and better quality control in the RCC structures, confinements in the joints as per the new provision of codes leading to the problem of the congestion. It has been observed at many construction sites that this congestion leads to poor workmanship at the joints, which actually making the joint more vulnerable than previous. Researcher has been working on this area to counter act by Increasing the size of the joints, Using the steel fiber in the joints, Using GRFP to wrap the joints, Prestressing the beam including the joint, Using of the crossed rebar at the joint cores. This paper tries to combine the benefits of the crossed rebar and prestressing in the joints together. The present work is divided into two phase. In first phase a family of planar building has been chosen and designed according to IS 456:2000 and shear force are calculated as per ACI 352-02. From this phase we come to conclusion that first two stories have higher shear force demand and these joints are more susceptible to congestion and prestessing of joint core should be implemented to these joints only. In the second phase exterior beam-column joint from previous experiments are chosen. They were model and analyse using ANSYS v13. Improvement in the ultimate load and failure pattern has been detailed in the thesis. From this phase we come to conclusion that this new technique is more effective than the previous prestressing technique of joints.